The prevalence for HIV in South Africa is 18% among 15-49 year old adults and 30% among female antenatal clinic attendees (UNAIDS, 2007), indicating continuing need for effective HIV prevention. Further, recent studies in sub-Saharan Africa found 60-94% of new HIV infections are occurring within marriage or co-habiting heterosexual partnerships (Dunkle et al., 2008). These findings signal the need for HIV prevention interventions that target couples in South Africa, This study will test the efficacy of a behavioral intervention program to increase HIV testing among couples living in Soweto, South Africa. The proposed theory-based, culturally appropriate intervention consists of six sessions (one mixed gender group, one single gender group, and four couples counseling sessions). Using a randomized controlled trial design with 350 heterosexual couples, we will test the hypothesis that compared with a single mixed gender group session, the proposed intervention will improve communication, intimacy and trust, which will lead to better communication about issues pertaining to HIV risk and testing, which in turn will improve couples' ability to negotiate safer sex and increase their participation in VCT for HIV. The intervention is based on preliminary research conducted by the PI via a K08 award from NIH, which was conducted in Soweto. The proposed study takes advantage of the infrastructure and collaborative relationships that the PI developed that enabled her to implement and conduct research within the Soweto community. The specific aims of the project are to test the efficacy of a theory-based and culturally appropriate couples- based intervention on the following outcomes: 1. Rates of testing for HIV. 2. Sexual risk behavior for HIV (with primary and any concurrent partners). In addition we will: 3. Evaluate the extent to which hypothesized mediating factors (e.g., relationship dynamics) explain the major outcomes and the extent to which the intervention affects these factors.